Karolina Wódz

Leukotriene receptor expression in mast cells is affected by their agonists

The effects of LTs are mediated by GPCRs: cysLTs interact with CYSLTR1, CYSLTR2, or GPR17, and LTB4 acts via BLT1R or BLT2R. Data relating to the presence of these receptors in mature tissue mast cells are not entirely known. By confocal microscopy with image analyses and flow cytometry, we established that native rat mast cells isolated from peritoneal cavity constitutively express all studied receptors. Moreover, we clearly documented that LTs by themselves can influence their own receptor expression. Low concentrations of LTs induce translocation of LT receptors from cell interior to plasma membrane, which can lead to increased mast cell responsiveness to LT stimulation. High concentrations of LTs cause internalization and, in consequence, reduction in the number of receptors on the cell surface, and it may result in desensitization of mast cells to subsequent LT stimulation. These observations may imply a physiological feedback mechanism regulating mast cell sensitivity to LT activation within tissues.

Repeated suberythemal UVB preexposure protects against high-dose UVB-induced expression of vitamin D receptor protein in human Skin.

pression in acquired nevi is reminiscent of the heterogeneity of B-RAF mutations found in human nevi (Lin et al., 2009). It remains to be determined whether the mutant B-RAF is coexpressed with p16 or if activated B-RAF and loss of p16 contribute separately to the clonal expansion of melanocytes. Alternatively, activated B-RAF and p16 deficiency may co-exist in a small percentage of nevus cells to enhance melanocyte proliferation and drive neoplastic transformation. The absence of a mutant-specific B-RAF antibody has so far precluded the execution of such an analysis. It is well established that activated B-RAF can promote nevus formation in murine and fish melanoma models (Patton et al., 2005; Goel et al., 2009), and the arrested state of nevi does not appear to require p16 (Dhomen et al., 2009). Nevertheless, the influence of p16 loss on the development of B-RAF-induced nevi needs to be investigated in human melanocytic tumors. This is particularly relevant as p16 loss regulates the penetrance and latency of B-RAF-induced murine melanomas (Dhomen et al., 2009).

Impact of Ultraviolet Radiation on Expression of Transforming Growth Factor β, Smad2, Metalloproteinases-1, -3, -8, -9, Cathepsin K and Progerin

Ultraviolet radiation (UVR) is one of the most important environmental factors involved in photoaging. Exposure to UVR leads to dysregulation of expression of cell cycle‐related proteins which play key role in skin photodegradation that pretends to develop carcinogenesis. This study examines the role of various UVB doses on the expression of transforming growth factor beta (TGF‐β), Smad2, cathepsin K, progerin and matrix metalloproteinases (MMPs)‐1,‐3,‐8,‐9. A group consisting of 63 healthy individuals underwent one of the following treatments: (1) whole body exposed to UVB irradiation on each of 10 consecutive days with 0.7 MED, or (2) whole‐body irradiation as described followed by a single erythemal UVB dose on a small body area, or (3) irradiated only with a single erythemal UVB dose on small body area, or (4) were not irradiated at all (control group). When we compared all irradiated groups to the control group, there was significantly higher expression of TGF‐β, MMP‐1,‐3,‐9 and cathepsin K proteins evaluated by Western blot method. The results suggest the role of UVB in impairment of proteins expression that is involved in cell cycles regulation. Changes in the protein expression involved by acute and chronic UVR confirm its essential role in skin photodestruction. Moreover, obtained result indicates the tendency to occurrence of photoadaptation phenomenon.

Proteins involved in cutaneous basal cell carcinoma development

Basal cell carcinoma (BCC) is the most common skin malignancy type in the Caucasian population, with a continuously increasing incidence rate. The etiology of BCC remains unknown, but it appears to have a multifactorial origin resulting from intrinsic and extrinsic factors, including short-wavelength ultraviolet B radiation. The role of specific proteins in BCC that are known to be responsible for the regulation of cell division and are involved in skin aging, including transforming growth factor (TGF)-β, Smad2, matrix metalloproteinases (MMPs)-1, -3, -8 and -9, cathepsin-K and progerin, remains unknown. The aim of the present study was to assess the mRNA and protein expression profile of samples with diagnosed nodular BCC (nBCC) compared with that of healthy skin samples collected from matched areas. The study group included 22 patients (10 men and 12 women; mean age, 59 years; range, 44-82 years) with pathologically confirmed nBCC, and 22 healthy volunteers (10 men and 12 women; mean age, 59 years; range, 43-78 years) as a control group. The expression of the studied proteins was assessed in all samples by western blotting and reverse transcription-quantitative polymerase chain reaction analysis. Statistically significant increases in the expression of TGF-β, Smad2, cathepsin-K, progerin and MMP-1, -3, -8 and -9 were detected in skin biopsies with diagnosed nBCC compared with the control group, confirming the important role of these proteins in skin carcinogenesis.

[Archaeons--still unknown microorganisms].

Archaea is a group of microorganisms described by Carl Woese in 1977. Although Archaea have a similar cellular organization to bacteria, their cell wall and cell membrane are quite unique. Archaeal cell wall lacks peptidoglican and cell membrane is composed of ether-lipids which are far more stable than bacteria-specific esther-lipids. Besides, Archaea have some specific external structures, like: archaella, pili, hami and cannulae but their exact functions are still unclear. Most of Archaea obtain energy via anaerobic processes of simple inorganic or organic compounds, however some of these organisms are also able to generate methane in the process known as methanogesis. They reproduce by cell division or budding-like process and some studies demonstrated the mechanisms of genetic transfer such as conjugation, transduction and natural transformation for the Archaea. They are capable of forming biofilms also in interaction with bacteria. Some archaeons, such as Haloferax mediterranei and Sulfolobus islandicus can synthesize antimicrobial agents which are called archaeocins. In recent years huge progress has been made in understanding of Archaea but many aspects of their biology remain still unknown. In this review, we present recent advances in Archaea biology focusing mainly on archaeal morphology, metabolism and reproduction.